Preserving composition for fibrous material.



KARL HEINRICH WOLMAN AND BERNARD DIAMAND, 0F IDAWEICHE, OBERSGHLE- SIEN, GERMANY,

ASSIGNOBS 'IOv MAX BARSCHALL, OF NIGE-CIMIEZ, FRANCE.

PRESERVING COMPOSITION FOR FIBROUS MATERIAL.

No Drawing.

To all whom it'may concern:

Be it known that we, KARL HEINRICH Wonunr, a subject of the Grand Duke of Baden, and BERNARD DIAMAND, a subject of the Emperor of Austria-Hungary, both residlng at Idaweiche, in Oberschlesien, in the Kingdom of Prussia, Germany, have invented certain new and useful Improvements in Preserving Fibrous Material, of which the following is a specification. V a

This invention relates to the art of preserving fibrous material such as wood, roofing-felt, cork-plates and other material composed of cellulose and other organic fiber, by-

treating the same with antiseptic compounds, preferably in the form of bath or solutions.

The object of the present invention is to take advantage, for this purpose, of the cheapness and preservation power of the metallic salts of strong mineral acids'such as sulfates, while, at the same time, avoiding the injurious and destructive PI'OPGI'tlGS which prevent the application of such sub-.

stances to the preservation of organic fiber.

The metallic salts of strong mineral acids such as sulfate of iron, sulfate of copper, and sulfate of aluminum, or mixtures of these salts which are generally used as impregnating agents, are objectionable in view of the fact that they are liable to be decomposed in the presence of water, forming a basic salt and free acid. As is known, free sulfuric acid or other equivalent mineral acid thus liberated acts injuriously on the organic fiber and thus a compound of this character, while preventing or retarding putrefication, exposes the fiber to destruction in another way, whereby its use is rendered more or less disadvantageous. In order to prevent this liberation of free mineral acid from the metallic salts employed as preserving agents, it has been proposed to add the salts of weak organic acids, for example, acetate of ammonia, to the impregnating solution. In this manner the weak acid only is liberated by the decomposition of the salt of the mineral acid which in the case of acetic acid is removed by volatilization. However, the addition of acetate of ammonia, which is wholly deficient in antiseptic qualities, diminishes the antiseptic properties of the solution inasmuch as the acetic acid to be volatilized acts as a diluent of the solution, having no antiseptic proper- Speciflcation of Letters Patent. Patented Sept 2,1 1909, Application filed November 6, 1906. Serial No. 342,307.

ties in itself, but on the contrary furnishing nourishment for the organisms destructive to the fiber.

It is, therefore, the furtherlobject of the invention to not only prevent the liberation of the injurious strong acid, but coincidently therewith to prevent the decrease in the antiseptic properties of the metallic salts when f adding such neutralizing agent.

For this purpose, the present invention consists in combining with the salt of a mineral acid, such as a metal sulfate, a substance capable of neutralizing free mineral acid and yielding or liberating when so combined an antiseptic. Preferably such substance should have antiseptic properties so combinedas in the examples hereinafter given. Such compounds may be used in various ways prefer to apply the same in the form of a bath, preferably a solution of such compounds.

Among the antiseptic substances to be combined with the metal salts of the strong mineral acids for preparing the antiseptic compound, which, as stated, is preferably in the form of a bath, we have found the alkali compounds of certain hydroxl containing derivatives of the hydrocarbons of the aromatic series, the hydroxl hydrogenthe most dilute sulfuric acid and will therefore neutralize the free sulfuric acid as quickly as formed. By adding them to the impregnating compound, or solution, they will therefore prevent the injurious action of the free sulfuric acid on the wood or other fibrous material. These alkali compounds of this group of bodies are themselves antiseptics, but their antiseptic action is even increased when these bodies themselves are liberated from the alkali compound by the mineral acid. Thus, as we have found, the addition of these antiseptic compounds produces a three-fold efiect: Firstly the antiseptic properties of the preserving compound or solution are increased; secondly, the injurious free mineral acid which may be formed is neutralized; thirdly,

the antiseptic action of the compound which I 1 is added is increased by the separation of may be employed. We have found thatgood resultswillbe obtained by employing -the free hydroxylated bodies therefrom.

In order-to carry out our invention it is notnecessary to separately use the above mentioned alkali compounds of the stated bodies in 'a ready prepared,,pure state, but crude solutions containing such compounds the alkaline aqueous solutions or washwaters obtained in the process of refining organic distillation products, such as crude petroleum, tar, tar-oil s, or the like by means of caustic'soda lye,'such solutions or washwaters containing phenolic and acid com- .ponents of raw petroleum, tar, tar-oil, or the like. These solutions orwash-waters may be used as obtained or they may be reduced to dryness to reduce their bulk and fit them for shipment.

. We find that the alkaline wash-waters, above-mentioned, other alkaline wash-waters obtained in refiningmhe products of the destrudtive distillation of resin orcolophony or the like, will also produce good and simi lar results and they are considered equivalent for this purpose. It is clear from the above that this improvement in the art has the further-merit of enabling waste produ'cts hitherto regarded as almost worthless to be utilized with advantage. We have also obtained good results by substituting for the above substances, for neutralizing free mineral acid and yielding an antiseptic body, salts of benzoic or salicilic acid, and

these are to be also considered as equivalents for the said substances. We have also found that the salts of hydrofluoric acid and of silicofiuoric acid' both of which are'weak, bactericidal acids when used in connection with a strong mineral acid, as above set forth, will produce good results in the above Ferrous sulfate 65 kilograms Aluminum sulfate 15 kilograms Sodium fluorid 10 kilograms Sodium silico-fluorid 10 kilograms 100 kilograms We prefer to add 50 kilograms of'this compound in solid form to 1000 liters of water and thereupon well boiling the whole when the same will be ready for use. Iron and aluminum fluorid and silicofluorids being soluble, the mixture described forms a solution.

The fibrous material, such as wood, roofingfelt, cork-plates or the like, may be impregnated by immersing the same into such solu-. tion or bath. The bath is kept at its original strength by adding 10 kilograms of the above material in solid form after the treatment of each cubic meter of the material. Care should also be taken to maintain the quantity of the bath that is to say, by adding snfiicient water after each operation with such material and before beginning the following operation. We find that one cubic meter of wood absorbs about cubic meter of the preserving bath, but since a considerable quantity of water is supplied by the condensation of the steam which is blown in during the impregnating operation, only little fresh water will be required after each operation. The impregnating bath may be used for years.

The following is an example of the application of an alkaline wash water obtained in refining an organic distillation product in the carrylng out of our invention. To obtain about 100 kilograms of our impregnat-.

ing compound in solid form, we first mix 65 kilograms of ferrous sulfate and 15 kilograms of aluminum sulfate. On the other hand we treat 300 kilograms of the so-called light oil (being the second product of the fractional distillation of brown-coal) with 15 kilograms of caustic soda lye containing 40 havlng separated the alkaline solution from the said light oil we reduce the solution to dryness. The residue is then pulverized and added to the aforesaid mixture of the inorganic salts. I

For the purpose of obtaining the impregnating compound in the form of solution, we dissolve 32.5 kilograms of ferrous sulfate and 7.5 kilo ams of aluminum sulfate in about 1000 liters of water and add 15 kilograms of the aforesaid alkaline wash-water. The aromatic phenols and acids contained in such wash-waters likewise form soluble iron and aluminum salts, so that no important precipitation by double decomposition occurs in forming the desired solution. The phenols'are weakly acid in nature, being frequently called acids, as in the case of carbolic acid, and in a free state are extremely bactericidal and antiseptic; as are also the aromatic acids.

. Having thus fully described our invention, what weclaim is 1. A preserving composition for fibrous material comprising a soluble mixture of a metallic salt of a strong mineral acid with the alkali extract of condensed products of destructive distillation.

per cent. of sodium hydroxid and after 2. A preserving bath comprising a solu- In testimony whereof We have hereunto tlon of a mixture of a metallic salt of a i set our hands in presence of two subscribing 10 strong mineral acid and the alkali extract Witnesses.

of condensed products of destructive (listilla- KARL HEINRICH VVOLMAN.

tion. BERNARD DIAM AND.

3. A preserving composition comprising a I \Vitnesses:

mixture of a metallic salt of a strong min- HENRY HASPER, eral acid with an alkali extract of tar. VVOLDEMAR HAUPT. 

